Question

cos square 75 --sin square 45​

Answer 1

Answer:

${cos}^{2} 75 - {sin}^{2} 45 \\ = cos(75 + 45)cos(75 - 45) \\ = cos120 \times cos30 \\ = - \frac{1 }{2} \times \frac{ \sqrt{3} }{2} \\ = - \frac{ \sqrt{3} }{4}$

Answer 2

Answer:

this is correct............................